Soil vent pipe
A soil vent pipe (SVP), also known as a soil stack pipe, drain-waste-vent or ventilated discharge pipe, is typically a vertical pipe that removes sewage and greywater from a building. It is often attached to the exterior of a building (although it may be fitted internally) and connects the subterranean drainage system to a point just above the level of the roof gutter.
Soil vent pipes allow the removal of waste from toilets, showers, baths and sinks, while also allowing odours to be released above the building, via a stack vent, at a level that will not cause a nuisance. The pipe’s vents also allow air into the internal drainage system so as to facilitate the process of aerobic sewage digestion, preventing a siphoning affect from occurring, and allowing free flow by gravity.
SVPs must maintain sufficient downward slope along their length to keep liquids and entrained solids flowing freely towards the drain. If a downward slope is not possible, a collection pit with a ‘sewage ejector’ pump can be installed.
Traditionally, soil vent pipes were made from cast iron; however, today they are most commonly made from uPVC.
Approved document H: Drainage and waste disposal requires that the foot of a discharge stack should have as large a radius as possible, and not less than 200 mm at the centre line. Offsets should be avoided in the wet section of the stack. Ventilating pipes should finish at least 900 mm above any opening within 3 m and should be finished with a wire cage or other perforated cover.
[edit] Related articles on Designing Buildings
Featured articles and news
A briefing on fall protection systems for designers
A legal requirement and an ethical must.
CIOB Ireland launches manifesto for 2024 General Election
A vision for a sustainable, high-quality built environment that benefits all members of society.
Local leaders gain new powers to support local high streets
High Street Rental Auctions to be introduced from December.
Infrastructure sector posts second gain for October
With a boost for housebuilder and commercial developer contract awards.
Sustainable construction design teams survey
Shaping the Future of Sustainable Design: Your Voice Matters.
COP29; impacts of construction and updates
Amid criticism, open letters and calls for reform.
The properties of conservation rooflights
Things to consider when choosing the right product.
Adapting to meet changing needs.
London Build: A festival of construction
Co-located with the London Build Fire & Security Expo.
Tasked with locating groups of 10,000 homes with opportunity.
Delivering radical reform in the UK energy market
What are the benefits, barriers and underlying principles.
Information Management Initiative IMI
Building sector-transforming capabilities in emerging technologies.
Recent study of UK households reveals chilling home truths
Poor insulation, EPC knowledge and lack of understanding as to what retrofit might offer.
Embodied Carbon in the Built Environment
Overview, regulations, detail calculations and much more.
Why the construction sector must embrace workplace mental health support
Let’s talk; more importantly now, than ever.
Ensuring the trustworthiness of AI systems
A key growth area, including impacts for construction.